SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7b243faac8315f09c0472a462e52e198be1d0a683d8fd2e6d95a9955d8fd430' 
  AND token = 'Eozmjn/ou2RdIlvRDehJeCHO9/IPbTQziEfh7AzkWq4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}